If a land grid has 0 neighboring land grid, its perimeter is 4

If a land grid has 4 neighboring land grids, its perimeter is 0

the perimeter decreases by 1 for every neighboring land grid.

```
int islandPerimeter(int** grid, int gridRowSize, int gridColSize) {
int numofneighbor = 0;
int perimeter = 0;
int i,j;
for (i=0; i< gridRowSize; i++) {
for (j=0; j<gridColSize; j++) {
if(*(*(grid+i)+j)) {
// this is a land
if (i-1>=0 && *(*(grid+i-1)+j)) {
numofneighbor ++;
}
if (i+1<gridRowSize && *(*(grid+i+1)+j)) {
numofneighbor++;
}
if (j-1>=0 && *(*(grid+i)+j-1)) {
numofneighbor++;
}
if (j+1< gridColSize && *(*(grid+i)+j+1)) {
numofneighbor++;
}
perimeter = perimeter + (4- numofneighbor);
numofneighbor = 0;
}
}
}
return perimeter;
}
```